You musicians may know this, but I discovered that if I enter anything above F# at the top of the treble clef for the French Horns, it's silent. It seems that although exceptional players can go higher, and Beethoven, at least, wrote a G above the treble clef, Notion SLE is silent above F#, although it will let you write a note there. I ended up giving the G to the clarinet.

I'm glad, personally, that Notion (and indeed Sibelius) restrict the range to normal levels! It is indeed, in the real world, extremely inadvisable to write anything above an F for Horns (or to dwell too long up there, from C#-F) - and am glad that notation software is playing it's part to stop composers venturing up to the stratosphere in their writing!

The instruments tessiture is restricted by miroslav. This is due to 2 things: First ability for an instrument to play range of notes, Second is the set of samples used when recording the instruments.

Above F# for horns is not a normal playing note for this instrument.If you want, there is a trick so that the above F# are playable, yet the sound can become bizarre. Using IK SampleTank (free and compatible with miroslav), one can modify the sample allocation to the keyboard and the range associated.